Preheat a smoker to 225 degrees F. (See Cook's Note)
Mix together the brown sugar, salt, cumin, granulated garlic, paprika, chili powder, onion powder, cayenne, black pepper and white pepper in a large bowl.
Trim the brisket so about 1/4-inch of fat remains. Apply the rub generously on all sides of the brisket, massaging it into the meat. Smoke the brisket until the internal temperature reaches approximately 155 degrees F, 4 to 5 hours depending on size.
Remove the brisket from the smoker and wrap in 2 layers of plastic wrap, followed by 1 layer of foil and a final layer of plastic wrap. Place in a roasting pan and continue cooking in an oven or smoker at 190 degrees F until very tender, another 16 to 18 hours. The brisket will be too tender to slice. Let cool, then refrigerate for 24 hours.
Slice the brisket into 1/2-inch-thick slices, preferably from the lean side, and place in the Lemongrass Marinade for at least 4 hours or up to overnight.
To build the sandwiches, spread some sriracha mayonnaise on the inside of the baguettes. Place some jalapenos on the bottom half of the bread and top with some brisket, scallions, pickled daikon and carrots, cucumber and cilantro.
Mix together the sugar, cola, lemongrass, black pepper, fish sauce, salt, peanut oil, sesame oil, garlic and shallots in a large bowl.
Pickled Daikon and Carrots:
Mix together the vinegar, sugar and salt in a bowl and stir until dissolved. Add the carrots and daikon and stir. Refrigerate overnight.
The best wood for the smoker is a blend of two-thirds apple wood to one-third hickory.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.